The display device comprises various signal lines, a switching element, a pixel electrode, etc. In the switching element, a semiconductor layer and a source/drain electrode are connected through a first contact hole, and another source/drain electrode and a pixel electrode are connected through a second contact hole. In a structure in which an organic insulating film is interposed between the source/drain electrode and the pixel electrode, there is a tendency that the depth of the second contact hole is increased, and the diameter is also increased. An area which overlaps the contact hole and a peripheral area of the contact hole become a part which has a large difference in level, and which does not contribute to display.
Requirement for higher definition has recently been increased in the display devices of nowadays, and while a size of one pixel is reduced, the number of lines used for wiring tends to be increased. Accordingly, there has been a demand for suppressing deterioration in display quality caused by, for example, a reduction of an opening which contributes to display.